The first step to fixing a knitting mistake is preventing a knitting mistake in the first place.  This first video shows you how to count stitches and rows in stockinette, reverse stockinette, and garter stitch fabric.  That way, if you set your knitting down, or lose your place, you can just count your stitches and rows to figure out where you were in the pattern.  

The second video shows you how to identify a knit stitch from a purl stitch.  Remember, a knit stitch looks like a v, and a purl stitch looks like a bump or a dash.  I also show you how to make sure that you stitches are seated correctly on your needle, what a twisted stitch looks like, and how to untwist that stitch.